1. Field of the Invention
The present invention relates to an information processor, an information processing method, and a computer program. More specifically, the present invention relates to an information processor, an information processing method, and a computer program, which realize usage control on a per-unit basis with respect to content stored on an information recording medium, and achieve strict usage control with respect to subsequently generated data such as data subsequently generated or downloaded by the user.
2. Description of the Related Art
Various software data, including audio data such as music, image data such as a movie, game programs, various application programs, and the like (hereinafter, these are referred to as “content”) can be stored as digital data onto a recording medium, for example, a Blu-ray Disc (trademark) using blue laser, a DVD (Digital Versatile Disc), an MD (Mini Disc), or a CD (Compact Disc). In particular, the Blu-ray Disc (trademark) using blue laser is a disc capable of high-density recording, which can record large-volume video content in the form of high image quality data.
Digital content is stored on various kinds of these information recording media (recording media) to be provided to the user. The user reproduces or uses the content using a reproducing device such as a PC (Personal Computer) or disc player the user owns.
For many kinds of content such as music data, image data, or the like, the distribution right or the like for the content is generally owned by the creator or seller of the content. Accordingly, the distribution of these kinds of content is generally subject to certain usage restrictions, that is, unauthorized duplication or the like is prevented by permitting only authorized users to use the content.
Digital recorders or recording media enable repeated recording and reproduction without causing, for example, a degradation of the image or sound quality. This has led to the problem that delivery of unauthorized copied contents over the Internet, circulation of so-called pirated discs produced by copying content onto a CD-R or the like, and use of copied content stored on a hard disk of a PC or the like are rampant.
A DVD, or a mass storage recording medium such as a recording medium using blue laser whose development has progressed in recent years allows a large volume of data equivalent to, for example, one to several tens of movies to be recorded on a single medium in the form of digital information. As it becomes possible to record video information and the like as digital information in this manner, it is becoming increasingly important to prevent unauthorized copying to protect the rights of copyright owners. In these days, in order to prevent such unauthorized copying of digital data, various technologies for preventing illegal copying have been implemented for digital recorders and recording media.
For example, Content Scramble System is adopted for DVD players. According to the Content Scramble System, video data, audio date, or the like is recorded on a DVD-ROM (Read Only Memory) in an encrypted form. A key used to decrypt the encrypted data is given to a licensed DVD player. The license is given to a DVD player designed to comply with predetermined operation requirements such as not to perform unauthorized copying. Accordingly, on the licensed DVD player, images or sound can be reproduced from a DVD-ROM by decrypting the encrypted data recorded on the DVD-ROM using the given key.
On the other hand, a DVD player that has not received the license cannot perform decryption of the encrypted data recorded on the DVD-ROM because it does not have the key necessary for decrypting the encrypted data. In this way, with the Content Scramble System, reproduction of data on a DVD-ROM recording digital data cannot be performed with a DVD player that does not satisfy the conditions required at the time of licensing, thereby preventing unauthorized copying.